Pd‐Loaded Carbon Felt as the Cathode for Selective Dechlorination of 2,4‐Dichlorophenoxyacetic Acid in Aqueous Solution

Electrocatalytic reductive dehalogenation of 2,4‐dichlorophenoxyacetic acid (2,4‐D) to phenoxyacetic acid in aqueous solution containing MeOH, trifluoroacetic acid, and tetraalkylammonium salt was studied A Tefton‐made two‐compartment flow‐through cell with a permeable carbon felt cathode and a platinum foil anode was employed. Several noble metals were tested as electrocatalysts. Palladium‐loaded carbon felt was found to be the most suitable cathode for selective dechlorination of 2,4‐D in aqueous solution. The preliminary electrolytic treatment of Pd/C cathode significantly enhanced its electrocatalytic activity toward 2,4‐D dechlorination. The reaction was hypothesized to proceed at carbon‐palladium interface areas through 4‐chlorine cleavage to form 2‐chlorophenoxyacetic acid as the main reaction intermediate.